JP2011048974A - Dye-sensitized solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell having a structure advantageous for improving water vapor barrier characteristics while improving a sealing property of an electrolyte. <P>SOLUTION: The solar cell includes: a substrate 1 with a light transmittance property having a light-incident surface 10 and a mounting surface 12; a transparent conductive film 2 formed on the mounting surface 12 of the substrate 1; a plurality of cells 3 of die-sensitizing types arranged on the transparent conductive film 2; an outer peripheral sealing part 4 forming an electrolyte chamber 50 for housing cells 3; the electrolyte 5 housed in the electrolyte chamber 50; an electrolyte-holding first back sheet 6 so bonded to the first outer peripheral sealing part 4 as to hold the electrolyte 5 of the electrolyte chamber 50; an outer peripheral sealing part 7 surrounding the outside of the first back sheet 6; and a second back sheet 8 which is bonded to the outer peripheral sealing part 7 and has a metal layer or a metal parent material for a water vapor barrier. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dye-sensitized solar cell.

  Dye-sensitized solar cells have attracted attention in recent years. A dye-sensitized solar cell includes a light-transmitting substrate having an incident surface on which light is incident and a mounting surface formed on the opposite side of the incident surface, and a transparent conductive material formed on the mounting surface of the substrate. A membrane, a dye-sensitized cell provided on the mounting surface side of the substrate, an electrolyte chamber provided on the mounting surface side of the substrate for accommodating the cell and surrounding the outside of the cell, and an electrolyte An electrolyte housed in the chamber, and an electrolyte holding backsheet portion joined to the outer peripheral seal portion so as to hold the electrolyte housed in the electrolyte chamber provided on the mounting surface side of the substrate (patent) References 1, 2). As the dye, for example, a ruthenium complex is employed. As the electrolyte, for example, an electrolyte solution containing iodine is employed. It is considered that electric energy is generated by utilizing a phenomenon in which a dye absorbs light and emits excited electrons, and a hole remaining in the dye oxidizes iodine in an electrolyte.

  According to the dye-sensitized solar cell described above, it is required to suppress water vapor from entering the inside. This is because the performance of the dye-sensitized solar cell changes when water vapor enters. Therefore, Patent Document 1 describes that a silane-modified resin is adopted as the material of the outer peripheral seal portion. According to this, water vapor barrier property can be improved.

  In order to further improve the water vapor barrier property, a dye-sensitized solar cell employing a structure in which an electrolyte chamber is closed by a back sheet portion having a structure in which a metal layer is laminated on a polymer material has been recently developed. According to this, the back sheet portion having a structure in which a metal layer is laminated on a polymer material has a function of enhancing the hermeticity of the electrolyte in the electrolyte chamber, and water vapor enters the inside of the dye-sensitized solar cell. It also has a water vapor barrier function that suppresses water. For this reason, even if it is used for a long period of time, it is suppressed that water vapor enters the inside of the dye-sensitized solar cell, and there is an advantage that the life of the dye-sensitized solar cell can be extended.

  However, in this case, if the thickness of the metal layer is increased in order to further increase the water vapor barrier function of the backsheet portion, the thickness of the polymer material layer that protects the metal layer is considered in view of ensuring the electrical insulation of the metal layer. Inevitably thickens. In this case, when manufacturing the dye-sensitized solar cell, thermal deformation such as thermal contraction of the backsheet portion tends to increase when the backsheet portion is heat-bonded (for example, heat fusion). Furthermore, even when the dye-sensitized solar cell is used, thermal deformation such as thermal contraction of the backsheet portion tends to increase due to the influence of the environmental temperature. In this case, the bonding strength of the backsheet portion may be affected, and the sealing performance against the electrolyte stored in the electrolyte chamber may be affected. However, if the thickness of the polymer material layer that protects the metal layer is reduced, the dielectric strength of the backsheet portion having the metal layer is lowered. Furthermore, even if the heating temperature for heating the backsheet portion during heat bonding is lowered, the bonding strength of the backsheet portion is affected, and there is a limit to improving the sealing performance for the electrolyte stored in the electrolyte chamber.

JP 2007-48504 A JP 2005-255781 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dye-sensitized solar cell having a structure advantageous for further improving the water vapor barrier property while improving the sealing property of the electrolyte.

  The present inventor has been diligently developing a dye-sensitized solar cell. And if the 1st back sheet | seat part for electrolyte holding which raises the sealing property of the electrolyte accommodated in the electrolyte chamber, and the 2nd back sheet | seat part which has a metal layer or metal base material for water vapor | steam barriers are provided separately, The dye-sensitized solar cell of the present invention has been developed by paying attention to the achievement of the above-described problems.

  A dye-sensitized solar cell according to the present invention includes: (i) a light transmissive substrate having an incident incident surface and a mounting surface formed on the opposite side of the incident surface; A transparent conductive film formed on the mounting surface; (iii) a plurality of dye-sensitized cells provided on the mounting surface side of the substrate and spaced from each other on the transparent conductive film; and (iv) mounting the substrate An outer peripheral seal portion that is provided on the surface side and that accommodates the cells and surrounds the outside of the plurality of cells; (v) an electrolyte that is accommodated in the electrolyte chamber; and (vi) is provided on the mounting surface side of the substrate. A first backsheet portion for holding the electrolyte joined to the outer peripheral seal portion so as to hold the electrolyte contained in the electrolyte chamber, and (vii) joining to a portion different from the first backsheet portion in the outer peripheral seal portion Metal layer or metal mother for water vapor barrier The first backsheet section which has a comprises a second backsheet section forming a separate.

  The outer peripheral seal portion is provided on the mounting surface side of the substrate, forms an electrolyte chamber that accommodates the cells, and surrounds the outside of the plurality of cells. The electrolyte is accommodated in the electrolyte chamber. The first back sheet portion is for holding the electrolyte, is provided on the mounting surface side of the substrate, and is joined to the outer peripheral seal portion so as to hold the electrolyte accommodated in the electrolyte chamber. Leakage of the electrolyte accommodated in the electrolyte chamber is suppressed by the first back sheet portion. The second backsheet portion is separate from the first backsheet and has a metal layer (barrier layer) or a metal base material for water vapor barrier. The entry of external water vapor into the inside of the dye-sensitized solar cell is suppressed by the second backsheet portion having water vapor barrier properties. The first backsheet portion and the second backsheet portion are separate from each other and are provided separately. For this reason, the first back sheet portion mainly plays a role of holding the electrolyte. The second back sheet portion mainly plays a role of suppressing the entry of water vapor.

  According to the present invention, the first backsheet portion for holding the electrolyte that enhances the sealing performance of the electrolyte accommodated in the electrolyte chamber is provided, and further, the second backhaul metal layer or metal base material for the water vapor barrier is provided. A back seat is provided as a separate body. For this reason, it is possible to further improve the water vapor barrier property while enhancing the sealing property of the electrolyte in the dye-sensitized solar cell.

It is sectional drawing of the dye-sensitized solar cell which concerns on Embodiment 1 and was cut | disconnected along the thickness direction of the board | substrate. It is a top view of the outer periphery seal | sticker part united with an intermediate seal part. It is sectional drawing of the principal part of a dye-sensitized solar cell. It is sectional drawing which shows the manufacturing process of a dye-sensitized solar cell. It is sectional drawing which shows the manufacturing process of a dye-sensitized solar cell. It is sectional drawing which shows the manufacturing process of a dye-sensitized solar cell. FIG. 6 is a cross-sectional view of a dye-sensitized solar cell (cell not shown) according to the second embodiment. FIG. 6 is a cross-sectional view of a main part of a dye-sensitized solar cell according to Embodiment 3. FIG. 6 is a cross-sectional view of a main part of a dye-sensitized solar cell according to Embodiment 4. FIG. 10 is a cross-sectional view of a main part of a dye-sensitized solar cell according to Embodiment 5. FIG. 10 is a cross-sectional view of a dye-sensitized solar cell (cell not shown) according to Embodiment 6. FIG. 10 is a cross-sectional view of a dye-sensitized solar cell according to Embodiment 7.

  According to one aspect of the present invention, the outer peripheral seal portion is provided adjacent to the first outer peripheral seal portion and the first outer peripheral seal portion that joins the first back sheet portion and surrounds the outside of the plurality of cells. And a second outer peripheral seal part for joining the sheet part. In this way, the first backsheet portion is joined to the first outer peripheral seal portion, and the second backsheet portion is joined to the second outer peripheral seal portion. As described above, the first backsheet portion for holding the electrolyte and the second backsheet portion for the water vapor barrier are arranged independently of each other.

  According to one aspect of the present invention, the second back sheet portion includes a metal layer having a water vapor barrier property and a back layer formed of a polymer material bonded to the metal layer. The metal layer is protected by the back layer. Moreover, according to one viewpoint of this invention, the 2nd back seat | sheet part is formed with the metal plate so that it may have a water vapor | steam barrier property. In this case, a high water vapor barrier property is obtained.

  According to one aspect of the present invention, a space is formed between the first backsheet and the second backsheet, but a space is substantially formed between the first backsheet and the second backsheet. It does not have to be.

  According to one aspect of the present invention, in the cross section cut along the thickness direction of the substrate, the outer wall surface of the outer peripheral seal portion has a structure protruding outward from the end surface in the length direction of the second backsheet portion. . The metal layer or metal base material of the second backsheet portion exhibits high water vapor barrier properties but has conductivity. Even when such a second back sheet portion has a metal layer or a metal base material, it is possible to effectively suppress the second back sheet portion from being in conductive contact with the transparent conductive film by the above structure.

  According to one aspect of the present invention, in the cross section cut along the thickness direction of the substrate, the outer peripheral seal portion has a covering portion that covers and seals the end surface in the length direction of the transparent conductive film from the outside. The second back sheet portion having the water vapor barrier property has a back sheet cover portion that covers the covering portion of the outer peripheral seal portion from the outside. It is possible to effectively prevent water vapor from passing through the outer peripheral seal portion and entering the electrolyte chamber.

(Embodiment 1)
FIG. 1 schematically shows a cross section of a dye-sensitized solar cell. As shown in FIG. 1, the dye-sensitized solar cell includes a substrate 1, a transparent conductive film 2 formed on the mounting surface 12 of the substrate 1, and a dye-sensitized solar cell provided on the mounting surface 12 side of the substrate 1. The cell group 30 formed of the plurality of cells 3, the first outer peripheral seal portion 4 provided on the mounting surface 12 side of the substrate 1, the electrolyte 5 accommodated in the electrolyte chamber 50, and the mounting surface 12 of the substrate 1. A first backsheet portion 6 having a film shape provided on the side, a second outer peripheral seal portion 7 provided on the mounting surface 12 side of the substrate 1, and a film shape provided on the mounting surface 12 side of the substrate 1. And a second backsheet portion 8.

  The substrate 1 is light transmissive and has an incident surface 10 on which light is incident and a mounting surface 12 formed on the opposite side of the incident surface 10. The substrate 1 may be inorganic glass or organic glass. The incident surface 10 and the mounting surface 12 are flat surfaces. The substrate 1 has a flat plate shape and has a length and a width in addition to the thickness. In the present specification, the term “length direction” includes the width direction.

  A transparent conductive film 2 is laminated on the mounting surface 12 of the substrate 1. The end 20 of the transparent conductive film 2 basically reaches the end face 1e in the length direction of the substrate 1 or the vicinity of the end face 1e. Examples of the material of the transparent conductive film 2 include tin oxide doped with fluorine or antimony, and ITO in which indium is substituted and dissolved in tin oxide. An insulating groove 2c is formed in the transparent conductive film 2, whereby the continuity of the transparent conductive film 2 is cut and the continuous conductivity of the transparent conductive film 2 is cut. The insulating groove 2c enhances the electrical insulation of each cell 3 and allows the cells 3 to be connected in series on the substrate 1. In this case, the adjacent cells 3 are electrically connected via a counter electrode 33 described later.

  A plurality of cells 3 are arranged on the transparent conductive film 2 so as to be spaced apart from each other, thereby forming a cell group 30. The single cell 3 includes a light receiving light electrode 31 stacked on the transparent conductive film 2, a separator 32 stacked on the photoelectrode 31, and a counter electrode 33 stacked on the separator 32. The light electrode 31 can receive light incident from the incident surface 10 of the substrate 1. The photoelectrode 31 is preferably formed by supporting a photosensitizing dye (having an electron emission property upon light irradiation) on an N-type semiconductor (anatase-type titanium oxide). The separator 32 is interposed between the photoelectrode 31 and the counter electrode 33 and is preferably formed of a rutile-type titanium oxide porous body. The counter electrode 33 is arranged at a predetermined interval with respect to the photoelectrode 31. The counter electrode 33 is preferably formed of an aggregate of carbon-based fine particles having high corrosion resistance and conductivity with respect to iodine, which is a halogen, or a metal material. Examples of the metal include titanium, tantalum, niobium, tungsten, and platinum. In this case, adjacent cells 3 are electrically connected via the counter electrode 33.

  As shown in FIG. 1, adjacent cells 3 are partitioned by a rib-shaped intermediate seal portion 45 that functions as a partition wall. As shown in FIG. 1, the first outer peripheral seal portion 4 surrounds the outer side of the cell group 30 formed of the plurality of cells 3 on the mounting surface 12 side of the substrate 1 so as to make one round. The first outer peripheral seal portion 4 and the intermediate seal portion 45 are preferably formed of a material that is chemically stable with respect to the electrolyte 5 and that does not elute substances harmful to the electrolyte 5. For example, polyisobutylene-based, polypropylene-based, polyethylene-based or other polyolefin-based materials, or copolymers thereof can be used. Here, it is preferable that the 1st outer periphery seal | sticker part 4 and the intermediate | middle seal part 45 are formed with the modified polyolefin type material which introduce | transduced the adhesive functional group into these polyolefin type materials. Specifically, it is preferably formed of a modified (adhesive) low density polyethylene into which a carboxyl group or the like is introduced as an adhesive functional group. The height of the first outer peripheral seal portion 4 and the height of the intermediate seal portion 45 with respect to the transparent conductive film 2 are preferably the same.

  As shown in FIG. 2, the first outer peripheral seal portion 4 has side portions 4a, 4b, 4c, and 4d, has a frame shape so as to make one round, and is connected to the intermediate seal portion 45. A plurality of electrolyte chambers 50 for accommodating the cells 3 are formed on the mounting surface 12 side of the substrate 1 together with the seal portion 45. The first outer peripheral seal portion 4 surrounds the plurality of electrolyte chambers 50 so as to make one round. As shown in FIG. 1, a fluid electrolyte 5 is accommodated in the electrolyte chamber 50. The electrolyte 5 can be an electrolytic solution in which the electrolyte 5 substance is dissolved in a solvent. In this case, as the solvent, a nitrile compound such as acetonitrile, methoxyacetonitrile, or propylonitrile can be used, or a solvent such as ethylene carbonate, propylene carbonate, or butylene carbonate, or a mixed solvent thereof can be used. A molten salt (ionic liquid) may be used instead of these solvents. The electrolyte 5 may be a solid electrolyte. The electrolyte 5 contains halogen ions (iodine ions).

  As shown in FIG. 1, the first backsheet portion 6 is for holding the electrolyte 5 so that the electrolyte 5 accommodated in the electrolyte chamber 50 does not leak, and thus seals the electrolyte chamber 50. Accordingly, the first back sheet portion 6 is joined to the joining surface 4c of the first outer peripheral seal portion 4 and the joining surface 45c of the intermediate seal portion 45 at a plurality of locations so as to hold the electrolyte 5 accommodated in the electrolyte chamber 50. Has been. The first backsheet portion 6 may be formed of a material that suppresses thermal shrinkage during heating such as heating and pressurization (for example, thermal fusion) or thermal shrinkage during use of a solar cell. preferable. In place of heating and pressing, laser beam fusion, ultrasonic welding, or the like can be used.

  Considering electrical insulation and gas barrier properties, the base material of the first backsheet 6 is polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or polybutylene naphthalate (PBN). ) Is preferred. Specifically, the first backsheet portion 6 is a base material layer formed of polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polybutylene naphthalate (PBN). And a second layer 62 laminated on the first layer 61 so as to face the first outer peripheral seal portion 4 and the intermediate seal portion 45. The first backsheet portion 6 may be formed of a first layer 61 and a second layer 62, or an intermediate layer such as an adhesive layer between the first layer 61 and the second layer 62 in the thickness direction. (Single layer or multiple layers) may be interposed.

  Since the second layer 62 of the first backsheet portion 6 is bonded to the first outer peripheral seal portion 4 and the intermediate seal portion 45, the second layer 62 has good bondability to the first outer peripheral seal portion 4 and the intermediate seal portion 45. It is preferable that it is made of a material. Therefore, the second layer 62 of the first backsheet portion 6 is preferably formed of the same material or a similar material as the first outer peripheral seal portion 4 and the intermediate seal portion 45. In this case, the second layer 62 of the first backsheet portion 6 has improved bondability to the first outer peripheral seal portion 4 and the intermediate seal portion 45. From the viewpoint described above, examples of the second layer 62 of the first backsheet portion 6 include polyisobutylene-based, polypropylene-based, polyethylene-based polyolefin-based materials, copolymers thereof, and the like. Here, it is preferable that the 1st outer periphery seal | sticker part 4 and the intermediate | middle seal part 45 are formed with the modified polyolefin type material which introduce | transduced the adhesive functional group into these polyolefin type materials. Specifically, it is preferably formed of a modified (adhesive) low density polyethylene into which a carboxyl group or the like is introduced as an adhesive functional group.

  As described above, according to the present embodiment, as a result, the first outer peripheral seal portion 4, the intermediate seal portion 45, and the second layer 62 are formed of a modified polyolefin material in which an adhesive functional group is introduced into the polyolefin material. It is preferable. Specifically, it is preferably formed of a modified (adhesive) low density polyethylene into which a carboxyl group or the like is introduced as an adhesive functional group. In this case, the modified (adhesive) low-density polyethylene contains a carboxyl group or the like as an adhesive functional group, so that the polarity is high and adhesion to the transparent conductive film 2 is ensured. The first backsheet portion 6 is made of a polymer material and does not embed a metal layer such as a metal foil. However, the 1st back seat | sheet part 6 may embed the metal layer as needed.

  As shown in FIG. 1, the second outer peripheral seal portion 7 has a frame shape so as to surround the outer side (outer peripheral side) of the first outer peripheral seal portion 4 on the mounting surface 12 side of the substrate 1. . Here, in order to mount the second back seat portion 8, the height h <b> 2 of the second outer peripheral seal portion 7 is set higher than the height h <b> 1 of the first outer peripheral seal portion 4. The second outer peripheral seal portion 7 is in contact with the outer wall surface 40 (outer peripheral surface) of the first outer peripheral seal portion 4 and adjacent to the ring portion 71 surrounding the outer side (outer peripheral side) of the first outer peripheral seal portion 4; A flange portion 72 provided integrally with the inner edge portion of the ring portion 71 toward the electrolyte chamber 50 is provided. The collar portion 72 covers and seals the end portion 60 of the first backsheet portion 6 from the opposite side of the substrate 1. Since the collar portion 72 extends in the shape of a collar, the joining area between the end portion 80 of the second backsheet portion 8 and the second outer peripheral seal portion 7 increases, and as a result, the joining force of the second backsheet portion 8 is increased. To be solid. In some cases, a gap may exist between the second outer peripheral seal portion 7 and the outer wall surface 40 (outer peripheral surface) of the first outer peripheral seal portion 4.

  The second outer peripheral seal portion 7 is preferably formed of a material having a high barrier property against water vapor permeation and gas permeation. Specifically, the second outer peripheral seal portion 7 is formed of butyl rubber, but may be formed of urethane rubber, chlorosulfonated polyethylene, nitrile rubber, or the like. This is also because the water vapor barrier property and the gas barrier property are high. The first outer peripheral seal portion 4 and the second outer peripheral seal portion 7 form an outer peripheral seal portion.

  The second back sheet portion 8 is for a water vapor barrier that suppresses external water vapor (including water as a liquid phase) from entering the electrolyte chamber 50, and covers the entire first back sheet portion 6 from the outside. Has been placed. Therefore, the end surface 8e in the length direction of the second back sheet portion 8 is more outward in the length direction of the substrate than the end surface 6e in the length direction of the first back sheet portion 6 in the entire circumference of the first back sheet portion 6. Located in the direction. The end portion 80 of the second back sheet portion 8 is joined to the joining surface 7 c of the second outer peripheral seal portion 7. Since the second back sheet portion 8 is a film that increases the water vapor barrier property, the second back sheet portion 8 includes a metal layer 81 having a high water vapor barrier property. Specifically, as shown in FIG. 1, the second back sheet portion 8 includes a planar metal layer 81 having a high water vapor barrier property and a polymer material bonded to one surface in the thickness direction of the metal layer 81. The outer back layer 82 on the side facing away from the second outer peripheral seal portion 7 and the polymer material bonded to the other surface in the thickness direction of the metal layer 81 and facing the second outer peripheral seal portion 7 And an inner back layer 83 on the side. The metal layer 81 is electrically insulated by the outer back layer 82 and the inner back layer 83.

  The outer back layer 82 is formed of a polymer material having high gas barrier properties, that is, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polybutylene naphthalate (PBN). Preferably it is. The inner back layer 83 is preferably formed of a material having good bonding properties to the second outer peripheral seal portion 7. Therefore, the inner back layer 83 is preferably formed of a modified polyolefin material in which an adhesive functional group is introduced into the polyolefin material. Specifically, the inner back layer 83 is formed of a modified (adhesive) low density polyethylene. Preferably it is.

  The metal layer 81 functioning as a water vapor barrier layer is preferably one that can exhibit higher water vapor barrier properties than the polymer material, and is preferably formed of an aluminum metal layer, a nickel layer, or the like. Aluminum may be pure aluminum or an aluminum alloy. The metal layer 81 may be formed of a metal sheet such as a metal foil or a metal film, or may be a layer in which metal fine particles are deposited in a film shape by a film forming means. The metal sheet such as metal foil may be a rolled sheet. Examples of film forming means include vapor deposition and sputtering.

  Thus, since the 2nd back seat | sheet part 8 has the metal layer 81 inside, the water vapor | steam barrier property higher than the 1st back seat | sheet part 6 is exhibited. Therefore, water vapor entering the inside of the dye-sensitized solar cell is suppressed for a long period of time. Therefore, changes in properties of the electrolyte 5 and the cell 3 held in the electrolyte chamber 50 are suppressed. The thickness tm of the metal layer 81 is preferably 5 micrometers or more, 10 micrometers or more, 15 micrometers or more, or 20 micrometers or more in consideration of the water vapor barrier property. As an upper limit of the thickness of the metal layer 81, although it changes also with the thickness of the 2nd back seat | sheet part 8, 200 micrometers and 300 micrometers are illustrated. However, it is not limited to these. Since the second back sheet portion 8 has the polymer material although having the metal layer 81, the second back sheet portion 8 is lighter than the case where the entire thickness of the second back sheet portion 8 is made of metal.

  However, in the second back sheet portion 8 having the metal layer 81 embedded, it is necessary to support the metal layer 81 while ensuring the electrical insulation and protection of the metal layer 81. For this reason, the thickness of the polymer material constituting the second back sheet portion 8, that is, the thickness ti of the inner back layer 83 and the thickness tp of the outer back layer 82 tend to increase more than necessary. Thus, since the inner back layer 83 thickness ti and the outer back layer 82 thickness tp constituting the second back sheet portion 8 tend to increase, the second back seat portion 8 is heated and pressurized to form the second outer peripheral seal portion. 7, when the heating temperature T <b> 2 is high, the thermal contraction of the second backsheet portion 8 increases, which may affect the sealing performance of the second backsheet portion 8. Therefore, according to the present embodiment, when the second backsheet portion 8 is joined to the second outer peripheral seal portion 7, the end portion 80 of the second backsheet portion 8 is pressure-bonded in the normal temperature region. Even if the end portion 80 of the second backsheet portion 8 is heated, the heating temperature T2 of the second backsheet portion 8 is set lower than the heating temperature T1 of the first backsheet portion 6. For example, the heating temperature T2 is preferably 110 ° C. or lower, 100 ° C. or lower, and 90 ° C. or lower.

  According to the present embodiment, when the thickness of the first backsheet portion 6 is tf and the thickness of the second backsheet portion 8 is ts, any of tf = ts, tf≈ts, tf <ts, tf> ts But it ’s okay. Considering that electrical insulation with respect to the cells 3 and the like is ensured by the first backsheet portion 6 that does not have the metal layer 81, the thickness ts of the second backsheet portion 8 can be reduced and tf> ts. Further, in consideration of increasing the thickness of the metal layer 81 and providing the second backsheet portion 8 with a high water vapor barrier property, tf <ts can be achieved.

  4 to 6 illustrate the manufacturing process. As shown in step (1) of FIG. 4, a substrate 1 having a transparent conductive film 2 laminated on a mounting surface 12 is prepared. As shown in step (2) of FIG. 4, an insulating groove 2 c is formed in the transparent conductive film 2 of the substrate 1. In this case, the groove 2c may be mechanically formed, or the groove 2c may be formed by irradiation with a high energy density beam such as a laser beam so that the strength of the substrate 1 can be secured. Thereafter, as shown in step (3) of FIG. 4, the photoelectrode 31 is laminated on the transparent conductive film 2 by a thin film forming method such as screen printing. Next, as shown in step (4) of FIG. 4, a separator 32 is laminated on the photoelectrode 31 by a thin film forming method such as screen printing. Further, as shown in step (5) of FIG. 5, the counter electrode 33 is laminated on the separator 32 by a thin film forming method such as screen printing. Thereby, the cell 3 in which the photoelectrode 31, the separator 32, and the counter electrode 33 are stacked is formed. The counter electrode 33 has a portion 33 a laminated on the separator 32 and a portion 33 c that comes into contact with and is in contact with the transparent conductive film 2. As shown in step (6) of FIG. 5, the first outer peripheral seal portion 4 and the intermediate seal portion 45 are laminated on the transparent conductive film 2 so as to partition the adjacent cells 3. Thereafter, as shown in step (7) of FIG. 5, the photoelectrode 31 is impregnated with the dye by the dye impregnation method. A ruthenium complex is illustrated as a pigment | dye. Thereafter, as shown in step (8) of FIG. 5, the electrolyte 5 (electrolytic solution) is accommodated in the electrolyte chamber 50 partitioned by the first outer peripheral seal portion 4 and the intermediate seal portion 45. Thereafter, as shown in step (1) of FIG. 6, the first back sheet portion 6 is heat-bonded (for example, heat-sealed) to the bonding surface 4c of the first outer peripheral seal portion 4 and the bonding surface 45c of the intermediate seal portion 45. . In this case, it is preferable to apply pressure while heating.

  Here, the heating temperature at the time of heat joining of the first back sheet portion 6 is T1. Considering the bonding strength, T1 is exemplified as being in the range of 120 to 220 ° C and in the range of 150 to 200 ° C. In this case, unlike the second backsheet portion 8, the first backsheet portion 6 does not have the metal layer 81, and the polymer material that protects the metal layer 81 does not have to be excessively thick. For this reason, the 1st back seat part 6 itself is a material or structure with few heat contractions. Therefore, even if the heating temperature T1 is set higher than the above-described heating temperature T2 in order to increase the bonding force, the thermal contraction of the first backsheet portion 6 during heating is suppressed. Similarly, even if the temperature of the first backsheet portion 6 is increased during use of the solar cell, thermal contraction of the first backsheet portion 6 is also suppressed. Thus, since the thermal contraction of the 1st back seat | sheet part 6 is suppressed, the fall of the sealing performance resulting from a thermal contraction is suppressed, and the protection with respect to the electrolyte 5 accommodated in the electrolyte chamber 50 can be improved.

  After the first back sheet portion 6 is joined to the joining surface 4c of the first outer peripheral seal portion 4 and the joining surface 45c of the intermediate seal portion 45 as described above, as shown in step (10) of FIG. The second outer peripheral seal portion 7 is formed on the transparent conductive film 2 by applying a type of butyl rubber to the transparent conductive film 2 of the substrate 1 in a frame shape and laminating it. In this case, adhesion to the transparent conductive film 2 can be further enhanced by applying pressure to the second outer peripheral seal portion 7.

  After the second outer peripheral seal portion 7 is formed, the end portion 80 of the second backsheet portion 8 is joined to the joining surface 7c of the second outer peripheral seal portion 7 as shown in step (11) of FIG. In this case, the second back sheet portion 8 may be mechanically pressure-bonded to the joint surface 7c of the second outer peripheral seal portion 7 in a normal temperature atmosphere. Alternatively, if necessary, the end portion 80 of the second backsheet portion 8 may be partially heated and pressed to be bonded to the bonding surface 7 c of the second outer peripheral seal portion 7. Further, it may be partially heated by a high energy density beam such as a laser beam or ultrasonic waves. However, when the second back sheet portion 8 is heated and bonded to the bonding surface 7c of the second outer peripheral seal portion 7 and the heating temperature when the second back sheet portion 8 is heated is T2 as described above, T2 <T1 Specifically, it is preferably 110 ° C. or less, particularly 40 to 100 ° C., preferably 60 to 90 ° C. This is because thermal deformation such as thermal shrinkage of the second back sheet portion 8 is suppressed and bonding strength is ensured.

  Through the above manufacturing process, the second back sheet portion 8 having the metal layer 81 is joined to the joining surface 7 c of the second outer peripheral seal portion 7. In this case, as shown in FIG. 1, the second backsheet portion 8 is on the side farther from the substrate 1 than the first backsheet portion 6 so as to cover the first backsheet portion 6 in the thickness direction of the substrate 1. Arranged via the space 87. When viewed from the direction of the arrow U in FIG. 1, the second backsheet portion 8 covers the entire first backsheet portion 6.

  As shown in FIG. 1, in order to increase the bonding area, etc., the flange portion 72 of the second outer peripheral seal portion 7 is formed so as to cover the end portion 60 of the first backsheet portion 6. A space 87 having a gap width hc is formed between the 1 backsheet portion 6 and the second backsheet portion 8 due to the thickness of the flange portion 72 of the second outer peripheral seal portion 7. The space 87 may be air or a reduced-pressure atmosphere. The space 87 reduces the inner surface 8i of the second backsheet portion 8 from interfering with or coming into contact with the outer surface 6p of the first backsheet portion 6. Therefore, even when the second backsheet portion 8 expands due to thermal expansion or the like during use, the inner surface 8i of the second backsheet portion 8 excessively interferes with or contacts the outer surface 6p of the first backsheet portion 6. This is suppressed, and the protection of both the back sheet portions 6 and 8 is ensured.

  However, in use, depending on the installation direction and installation location of the dye-sensitized solar cell, when the thermal expansion of the second backsheet portion 8 is large, the inner surface 8i of the second backsheet portion 8 is affected by the gravity. There is a possibility that the frequency of contact with the outer surface 6p of the backsheet portion 6 increases. Even in such a case, according to the present embodiment, the first backsheet portion 6 and the second backsheet portion 8 are independent from each other and are fixed to independent portions. Further, the second back sheet portions 8 are not joined to each other, and the inner surface 8 i of the second back sheet portion 8 can be displaced relative to the outer surface 6 p of the first back sheet portion 6. Therefore, the relative displacement of the inner surface 8 i of the second backsheet portion 8 is suppressed from affecting the outer surface 6 p of the first backsheet portion 6.

  In the cross section shown in FIG. 1 (cross section cut along the length direction and the thickness direction of the substrate 1), the length of the first backsheet portion 6 is Lf, the length of the substrate 1 is Lb, and the transparent conductive When the length of the film 2 is Lt and the length of the second outer peripheral seal portion 7 is Ls, Lf is shorter than Ls, Lb, and Lt. Ls is shorter than Lb and Lt. Therefore, the end portion 20 of the transparent conductive film 2 is exposed outward in the length direction of the substrate from the second outer peripheral seal portion 7. As shown in FIG. 1, the end surface 8 e in the length direction of the second backsheet portion 8 is ΔW (0... 0) on the inner side (electrolyte chamber 50 side) than the outer wall surface (outer peripheral surface) 70 of the second outer peripheral seal portion 7. (5 mm or more, 1 mm or more). Although the metal layer 81 has a high water vapor barrier property, it also has conductivity and may be exposed to the end face 8e. For this reason, even when the second backsheet portion 8 having a polymer material as a base material in addition to the metal layer 81 is bent during use, it is embedded in the second backsheet portion 8 by the withdrawal of ΔW. The conductive metal layer 81 is prevented from contacting the transparent conductive film 2 on the substrate 1 and conducting. At the time of use, the dye-sensitized solar cell having the first structure can be covered with a moisture-proof layer using a resin as a base material. In use, the dye-sensitized solar cell is disposed so that the incident surface 10 of the substrate 1 faces the light source.

  As described above, according to the present embodiment, the second backsheet portion 8 that is separate from the first backsheet portion 6 is used for a water vapor barrier, and the second backsheet portion 8 has an improved water vapor barrier property. Accordingly, a metal layer 81 is laminated. For this reason, when using a dye-sensitized solar cell, the entry of external water vapor into the inside of the dye-sensitized solar cell is suppressed for a long period of time, which can contribute to extending the life of the dye-sensitized solar cell. . As described above, the water vapor barrier property is achieved by the second back sheet portion 8 arranged separately from the first back sheet portion 6 outside the first back sheet portion 6. For this reason, the metal layer 81 does not have to be embedded in the first back sheet portion 6 for holding the electrolyte 5 accommodated in the electrolyte chamber 50. Therefore, in the first backsheet portion 6 for holding the electrolyte, it is not necessary to make the thickness of the polymer material constituting the first backsheet portion 6 excessive in order to protect the metal layer.

  Thus, according to this embodiment, since the excess of the polymeric material which comprises the 1st back seat | sheet part 6 is suppressed, the edge part 60 of the 1st back seat | sheet part 6 is connected to the 1st outer periphery seal | sticker part 4. FIG. Even when heat joining is used to join the joining surface 4c and the joining surface 45c of the intermediate seal portion 45, excessive thermal shrinkage of the first backsheet portion 6 is suppressed. Therefore, according to this embodiment, it is suppressed effectively that the sealing performance of the 1st back seat | sheet part 6 falls because of the heat shrink by heating at the time of a manufacture process. In this case, electrical insulation by the first back sheet portion 6 is ensured, and it is advantageous for suppressing leakage of the electrolyte 5 accommodated in the electrolyte chamber 50.

  Furthermore, even when the temperature of the dye-sensitized solar cell is raised by the atmosphere during use, excessive heat shrinkage of the first backsheet portion 6 is suppressed. As a result, the sealing performance between the first back sheet portion 6 and the first outer peripheral seal portion 4 is favorably maintained over a long period. Similarly, the sealing performance between the first back sheet portion 6 and the intermediate seal portion 45 is maintained well. As a result, the sealing performance with respect to the electrolyte 5 accommodated in the electrolyte chamber 50 can be improved over a long period of time, and the reliability of the dye-sensitized solar cell can be improved and the lifetime can be increased.

  As described above, since the second back sheet portion 8 is used for the water vapor barrier, the metal layer 81 such as a metal foil having a barrier property higher than that of the polymer material is embedded and laminated. For this reason, for the second backsheet portion 8, in order to enhance the protection of the metal layer 81, while ensuring the required water vapor barrier properties, the thickness of the polymer material constituting the second backsheet portion 8, that is, The thickness of the inner back layer 83 and the thickness of the outer back layer 82 tend to increase. For this reason, if the second back sheet portion 8 is heated when the second back sheet portion 8 is heated in the case where the second back sheet portion 8 is joined to the second outer peripheral seal portion 7, There is a tendency that the amount of heat shrinkage of the backsheet portion 8 increases. Excessive heat shrinkage is not preferable in order to maintain high sealing performance. In this regard, according to the present embodiment, the end portion 80 of the second backsheet portion 8 in which the metal layer 81 is embedded in the polymer material is mechanically pressure-bonded to the joining surface 7c of the second outer peripheral seal portion 7 and joined. I will let you. In some cases, even if the second backsheet portion 8 is heated and bonded to the bonding surface 7c of the second outer peripheral seal portion 7, the temperature T2 for heating the second backsheet portion 8 is in a relationship of T2 <T1. The temperature is lower. For this reason, when the 2nd back seat | sheet part 8 is heat-joined to the 2nd outer periphery seal | sticker part 7, the heating temperature T2 is made low. Even if the heating temperature T is lowered, the leakage prevention and electrical insulation of the electrolyte 5 are sufficiently ensured by the first back sheet portion 6, so that there is no particular problem. As described above, according to the present embodiment, excessive heat shrinkage of the second backsheet portion 8 during manufacturing is suppressed, deterioration of the sealing performance of the second backsheet portion 8 is suppressed, and high water vapor barrier properties are achieved. can get.

  According to the present embodiment, the second back sheet portion 8 is formed by sandwiching the metal layer 81 from both sides in the thickness direction between the outer back layer 82 and the inner back layer 83 formed of a polymer material. Therefore, the outer back layer 82 and the inner back made of a polymer material rich in elasticity even when the metal constituting the metal layer 81 and the polymer material have different thermal expansion coefficients during use. Layer 83 can follow.

  According to this embodiment, the metal layer 81 is embedded in the second back sheet portion 8, but is not embedded in the first back sheet portion 6. Therefore, even if the first backsheet portion 6 disposed closer to the cell 3 than the second backsheet portion 8 is damaged due to unexpected circumstances, the metal can exhibit conductivity. It is possible to prevent the layer and the cell 3 from contacting and conducting. Between the metal layer 81 embedded in the second backsheet portion 8 and the cell 3, the first backsheet portion 6 made of a polymer material and having high electrical insulation is disposed. Even if the second backsheet portion 8 is damaged due to unforeseen circumstances, the metal layer 81 embedded in the second backsheet portion 8 and the cell 3 are prevented from contacting and conducting.

  As shown in FIG. 1, the second outer peripheral seal portion 7 is formed so as to surround and cover the first outer peripheral seal portion 4 from the outer peripheral side while contacting or joining to the outer peripheral side of the first outer peripheral seal portion 7. ing. For this reason, the protection property of the first outer peripheral seal 4 can be improved, and the protection property of the first backsheet portion 6 joined to the first outer peripheral seal portion 4 can be improved, thereby contributing to the prevention of leakage of the electrolyte 5 in the electrolyte chamber 50. it can.

  In addition, the test piece of the actual solar cell manufactured as mentioned above was created, and the durability test was done. In the test piece, the metal layer 81 of the second backsheet portion 8 was made of an aluminum foil and had a thickness tm of 10 micrometers. The outer back layer 82 of the second backsheet portion 8 is made of PET and has a thickness of 10 micrometers. The inner back layer 83 of the second backsheet portion 8 is made of polyethylene and has a thickness of 50 micrometers. About the 1st layer 61 of the 1st back seat | sheet part 6, the material was PEN and thickness was 100 micrometers. About the 2nd layer 62 of the 1st back seat | sheet part 6, the material was polyethylene and thickness was 50 micrometers. In this test, when the initial performance after the solar cell test piece was left for 1000 hours in an atmosphere at a temperature of 85 ° C. and a relative humidity of 85% was measured, the maintenance rate of the initial performance of the dye-sensitized solar cell was improved. . This is probably because the entrance of water vapor is well prevented.

(Embodiment 2)
FIG. 7 shows a second embodiment. This embodiment basically has the same configuration and the same function and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 7, the end portion 80 in the length direction of the second backsheet portion 8 is located outside the outer wall surface 70 (outer peripheral surface) of the second outer peripheral seal portion 7 along the length direction of the substrate 1. Protrusively by ΔW2. The second back sheet portion 8 has a metal layer 81. Since ΔW2 is shorter than the height h2 of the second outer peripheral seal portion 7, the end portion 80 in the length direction of the second backsheet portion 8 formed of the polymer material is suppressed from being excessively bent. . Accordingly, the metal layer 81 at the end 80 of the second backsheet portion 8 is prevented from being in conductive contact with the transparent conductive film 2 on the substrate 1. In FIG. 7, the cell 3 is omitted in order to avoid complication of the drawing.

(Embodiment 3)
FIG. 8 shows a third embodiment. This embodiment basically has the same configuration and the same function and effect as the first embodiment. Hereinafter, the description will focus on the different parts. The second back sheet portion 8 has a metal layer 81 embedded in order to exhibit a water vapor barrier. The metal layer 81 is exposed on the end surface 8 e in the length direction of the second backsheet portion 8. Although the metal layer 81 exhibits the advantage of exhibiting a high water vapor barrier, since it has conductivity, it is preferable to prevent conduction with the transparent conductive film 2 on the substrate 1. Therefore, as shown in FIG. 8, the outer wall surface 70 of the second outer peripheral seal portion 7 is more outward (in the length direction of the substrate 1) than the end surface 8 e of the end portion 80 in the length direction of the second backsheet portion 8. Protrusively by ΔW30. In other words, the end surface 8e of the end portion 80 in the length direction of the second back seat portion 8 is retracted by ΔW30 toward the inside, that is, toward the electrolyte chamber 50, rather than the outer wall surface 70 of the second outer peripheral seal portion 7. is doing. For this reason, it is suppressed that the metal layer 81 having conductivity embedded in the end portion 80 of the second back sheet portion 8 is bent toward the transparent conductive film 2 side of the substrate 1 and directly conducted.

Further, as shown in FIG. 8, the outer wall surface 70 of the second outer peripheral seal portion 7 is more outward (the length of the substrate 1 than the end surface 1 e in the length direction of the substrate 1 and the end surface 2 e in the length direction of the transparent conductive film 2. It projects by ΔW32 toward (in the vertical direction). Also in this meaning, it is suppressed that the edge part 80 of the 2nd back seat | sheet part 8 bends to the transparent conductive film 2 side of the board | substrate 1, and is conduct | electrically_connected. Note that since ΔW30> ΔW32, the conduction is effectively suppressed. However, ΔW30≈ΔW32 may be satisfied, or ΔW30 <ΔW32 may be satisfied.
(Embodiment 4)
FIG. 9 shows a fourth embodiment. This embodiment basically has the same configuration and the same function and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 9, the second outer peripheral seal portion 7 has a covering portion 78. The covering portion 78 is bent at approximately 90 degrees toward the end surface 1e side of the substrate 1, and covers the end surface 1e in the length direction of the substrate 1 and the end surface 2e in the length direction of the transparent conductive film 2 from the outside. The protection of the end face 2e is enhanced. Further, as shown in FIG. 9, the back sheet cover portion 85 corresponding to the end portion of the second back sheet portion 8 is bent toward the end surface 1e side of the substrate 1, and covers the covering portion 78 from the outside. ing. The back sheet cover part 85 is a part of the second back sheet part 8, has a metal layer 81 embedded therein, and has a high water vapor barrier property. The back sheet cover portion 85 having such a high water vapor barrier property surrounds the covering portion 78 of the second outer peripheral seal portion 7 from the outside. For this reason, it is suppressed that external water vapor enters the electrolyte chamber 50 from the covering portion 78 through the second outer peripheral seal portion 7, which can further contribute to the longer life.

  Further, as shown in FIG. 9, the end surface 78e of the covering portion 78 of the second outer peripheral seal portion 7 is closer to the incident surface 10 side of the substrate 1 than the end surface 85e of the backsheet cover portion 85 of the second backsheet portion 8. Have entered the market. For this reason, the metal layer 81 of the second back sheet portion 8 is effectively suppressed from being in conductive contact with the transparent conductive film 2 on the substrate 1. As shown in FIG. 9, the end surface 2 e in the length direction of the transparent conductive film 2 is covered from the outside of the end surface 2 e by the covering portion 78 of the second outer peripheral seal portion 7. For this reason, the metal layer 81 of the second back sheet portion 8 is more effectively suppressed from being in conductive contact with the transparent conductive film 2 on the substrate 1. The covering portion 78 and the backsheet cover portion 85 of the second outer peripheral seal portion 7 are preferably covered over the entire periphery of the end surface 1 e of the substrate 1.

  Here, the covering portion 78 together with the second outer peripheral seal portion 7 is formed of a material having a high gas barrier property such as butyl rubber. Further, the back sheet cover portion 85 of the end portion 80 of the second back sheet portion 8 on which the metal layer 81 exhibiting high water vapor barrier properties is laminated covers the covering portion 78 from the outside. As a result, it is further suppressed that water vapor permeates the second outer peripheral seal portion 7 and enters the electrolyte chamber 50, which can further contribute to the extension of the life of the dye-sensitized solar cell.

  As the metal layer 81 embed | buried under the 2nd back seat | sheet part 8, it can form with metal foil, for example. The metal foil itself has flexibility. Even when the second back sheet portion 8 is bent so as to form the bent portion 8r, the metal foil can follow the bending of the second back sheet portion 8. The metal foil may be in the form of a flat foil, or a metal foil in which a large number of wrinkles are formed. In this case, even when the bending angle of the second back sheet portion 8 is large, the wrinkles can increase the flexibility of the metal foil.

(Embodiment 5)
FIG. 10 shows a fifth embodiment. This embodiment basically has the same configuration and the same function and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 10, even if the end portion 80 in the length direction of the second backsheet portion 8 is bent, a space of ΔW5 is formed between the transparent conductive film 2 and the second backsheet portion 8. Therefore, the end surface 8e (the metal layer 81 exposed on the end surface 8e) of the end portion 80 of the second backsheet portion 8 is prevented from landing on the transparent conductive film 2 on the substrate 1. Therefore, the metal layer 81 exposed on the end face 8 e is prevented from being in conductive contact with the transparent conductive film 2 on the substrate 1. Thus, the length ΔLc of the second back sheet portion 8 that protrudes outward from the second outer peripheral seal portion 7 is limited.

(Embodiment 6)
FIG. 11 shows a sixth embodiment. This embodiment basically has the same configuration and the same function and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 11, the end surface 8 e in the length direction of the second back sheet portion 8 </ b> B protrudes by ΔW2 outward from the outer wall surface 70 of the second outer peripheral seal portion 7. However, the second back sheet portion 8B is formed of a metal plate having higher rigidity than the polymer material, and is joined to the joining surface 7c of the second outer peripheral seal portion 7 via an adhesive. The joint surface 7c of the second outer peripheral seal portion 7 is formed of a polymer material. For this reason, the joining property and sealing property of the 2nd back seat | sheet part 8B and the joint surface 7c of the 2nd outer periphery seal | sticker part 7 are ensured.

  As described above, the metal plate (for example, aluminum, aluminum alloy, iron alloy, stainless steel) constituting the second back sheet portion 8B has higher rigidity than the polymer material. Therefore, it is suppressed that the edge part 80 of the 2nd back seat | sheet part 8B formed with the metal plate bends. Therefore, the end portion 80 of the second back sheet portion 8B is prevented from being bent and conducting contact with the transparent conductive film 2 on the substrate 1. The thickness of the metal plate is preferably smaller than the thickness of the substrate 1 and is preferably reduced in weight.

  Furthermore, according to the present embodiment, in the thickness direction of the substrate 1, the cell group formed of cells is sandwiched between the highly rigid substrate 1 formed of glass and the highly rigid metal plate. For this reason, even when the second outer peripheral seal portion 7 and the first outer peripheral seal portion 4 are formed of a polymer material, high rigidity is obtained as a whole. Therefore, the durability of the dye-sensitized solar cell is improved. In FIG. 11, the cells are not shown in order to avoid complication of the drawing. In some cases, the base material of the plate constituting the second backsheet portion 8B can be ceramic such as alumina.

(Embodiment 7)
FIG. 12 shows a seventh embodiment. This embodiment basically has the same configuration and the same function and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 12, a frame-shaped first outer peripheral seal portion 4 </ b> C is laminated on the transparent conductive film 2 on the substrate 1. And the end part 60 of the 1st back seat | sheet part 6 is mounted on the 1st outer periphery seal | sticker part 4C, and is joined. Next, the frame-shaped second outer peripheral seal portion 7C is placed on and joined to the first back sheet portion 6 and the first outer peripheral seal portion 4C. Thus, the outer peripheral seal portions 4C and 7C are provided adjacent to each other in the thickness direction of the substrate 1.

  Also in this embodiment, as shown in FIG. 12, the 1st back seat | sheet part 6 for electrolyte holding which improves the sealing property of the electrolyte 5 accommodated in the electrolyte chamber 50 is provided. Furthermore, the 2nd back sheet | seat part 8 which has metal layers 81, such as metal foil for water vapor | steam barriers, is provided as a different body. Therefore, it is possible to improve the water vapor barrier property while improving the sealing property of the electrolyte 5 accommodated in the electrolyte chamber 50.

  (Others) According to the above-described embodiment, the lower limit value and the upper limit value of the thicknesses of the first layer 61, the second layer 62, the metal layer 81, and the outer back layer 82 can be exemplified as follows. As the lower limit values, the first layer 61 can be 5 μm or more and 10 μm or more, the second layer 62 can be 5 μm or more and 50 μm or more, the metal layer 81 can be 5 μm or more and 10 μm or more, and the outer back layer 82 can be 5 μm or more. , 50 μm or more. Examples of the upper limit include 250 μm or less, 150 μm or less, or 100 μm or less for any layer. However, it is not limited to these. According to the first embodiment, the first backsheet portion 6 is formed of a first layer 61 formed of PPE, PET, PBT, or PBN, and a second layer 62 laminated integrally with the first layer 61. However, the present invention is not limited to this, and it may be formed only by the first layer 61 or may be formed only by the second layer 62. The first backsheet portion may be formed of a first layer 61 formed of PPE, PET, PBT, or PBN and a second layer 62 that is separate from the first layer 61. In short, after the first layer 61 is joined to the joint surface 4 c of the first outer peripheral seal portion 4, the second layer 62, which is a separate body from the first layer 61, is joined to the first layer 61. Also good. Although it is preferable that the first back sheet portion 6 does not have a metal layer, a thin metal layer may be embedded in the first back sheet portion 6 as long as the bonding property of the first back sheet portion 6 can be sufficiently secured.

  The first outer peripheral seal portion 4 and the intermediate seal portion 45 are preferably formed of a modified (adhesive) low density polyethylene introduced with an adhesive functional group, but a modified (adhesive) medium density introduced with an adhesive functional group. It may be formed of polyethylene or high density polyethylene, and may be formed of other materials. In some cases, the first outer peripheral seal portion and the second outer peripheral seal portion may be formed of metal. In this case, an adhesive can be used to join the first backsheet portion 6 and the second backsheet portion 8 to the first outer peripheral seal portion and the second outer peripheral seal portion. The base material is not limited to the second back sheet portion 8 having the metal layer or metal base material for the water vapor barrier, but a metal oxide layer (ceramic layer such as alumina) or metal oxide (ceramic material such as alumina) for the water vapor barrier. You may use a 2nd back seat | sheet part. In the above-described embodiment, the first backsheet portion 6 and the second backsheet portion 8 are provided at an interval, but if the first backsheet portion 6 and the second backsheet portion 8 are not joined, They may be in contact with each other. Although the first backsheet portion 6 and the second backsheet portion 8 are not joined to each other, in some cases, the first backsheet portion 6 and the second backsheet portion 8 may be partially joined to each other. good.

  The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not departing from the gist. The following technical idea can also be grasped from the description of the present specification.

  (Additional Item 1) A light-transmitting substrate having an incident surface on which light is incident and a mounting surface formed on the opposite side of the incident surface, a transparent conductive film formed on the mounting surface of the substrate, A plurality of dye-sensitized cells provided on the substrate mounting surface side and spaced apart from each other on the transparent conductive film, and a plurality of electrolyte chambers provided on the substrate mounting surface side for accommodating the cells are formed. An outer periphery seal portion that surrounds the outside of the cell, an electrolyte housed in the electrolyte chamber, and an electrolyte holder that is joined to the outer periphery seal portion so as to retain the electrolyte that is provided on the mounting surface side of the substrate and housed in the electrolyte chamber A dye-sensitized solar cell comprising a backsheet portion for use.

  (Additional Item 2) A light-transmitting substrate having an incident surface on which light is incident and a mounting surface formed on the opposite side of the incident surface, a transparent conductive film formed on the mounting surface of the substrate, A plurality of dye-sensitized cells provided on the substrate mounting surface side and spaced apart from each other on the transparent conductive film, and a plurality of electrolyte chambers provided on the substrate mounting surface side for accommodating the cells are formed. An outer peripheral seal portion that surrounds the outside of the cell, an electrolyte accommodated in the electrolyte chamber, and an electrolyte joined to the outer peripheral seal portion so as to hold the electrolyte that is provided on the mounting surface side of the substrate and accommodated in the electrolyte chamber The first backsheet portion for holding and the base material having a water vapor barrier layer or a water vapor barrier bonded to a portion different from the first back sheet portion in the outer peripheral seal portion and separate from the first back sheet portion Second back sea Dye-sensitized solar cell and a part. Examples of the water vapor barrier layer include a metal layer and a ceramic layer.

  The present invention can be used for a power generator using a dye-sensitized solar cell.

  1 is a substrate, 1e is an end surface, 10 is an incident surface, 12 is a mounting surface, 2 is a transparent conductive film, 20 is an end, 2e is an end surface, 3 is a cell, 30 is a cell group, 31 is a photoelectrode, 32 is a separator , 33 is a counter electrode, 4 is a first outer peripheral seal part, 40 is an outer wall surface, 45 is an intermediate seal part, 5 is an electrolyte, 50 is a charge chamber, 6 is a first backsheet part, 61 is a first layer, 62 Is the second layer, 60 is the end portion, 7 is the second outer peripheral seal portion, 8 is the second backsheet portion, 80 is the end portion, 81 is the metal layer, 82 is the outer back layer, 83 is the inner back layer, 85 is A back seat cover portion 87 indicates a space.

Claims (6)

A light-transmitting substrate having an incident surface on which light is incident and a mounting surface formed on the opposite side of the incident surface;
A transparent conductive film formed on the mounting surface of the substrate;
A plurality of dye-sensitized cells provided on the mounting surface side of the substrate and spaced apart from each other in the transparent conductive film;
An outer peripheral seal portion that is provided on the mounting surface side of the substrate and that forms the electrolyte chamber that houses the cells and surrounds the outside of the plurality of cells;
An electrolyte contained in the electrolyte chamber;
A first backsheet portion for holding an electrolyte, which is provided on the mounting surface side of the substrate and joined to the outer peripheral seal portion so as to hold the electrolyte contained in the electrolyte chamber;
A second backsheet portion which is joined to a portion different from the first backsheet portion in the outer peripheral seal portion and has a metal layer or a metal base material for a water vapor barrier and separate from the first backsheet portion; A dye-sensitized solar cell provided.   In Claim 1, The said outer periphery seal | sticker part adjoins the said 1st back seat | sheet part, and surrounds the outer side of the said several cell, The said 2nd periphery seal part is provided adjacent to the said 1st outer periphery seal | sticker part. A dye-sensitized solar cell including a second outer peripheral seal portion to which the backsheet portion is bonded.   3. The dye-sensitized type according to claim 1, wherein the second back sheet portion includes a metal layer having a water vapor barrier property and a back layer formed of a polymer material bonded to the metal layer in a laminated state. Solar cell.   3. The dye-sensitized solar cell according to claim 1, wherein the second back sheet portion is formed of a metal plate having a water vapor barrier property.   5. The cross-section cut in the thickness direction of the substrate according to claim 1, wherein the outer wall surface of the outer peripheral seal portion is more than the end surface in the length direction of the second back sheet portion. A dye-sensitized solar cell that protrudes outward in the length direction.   5. The coating according to claim 1, wherein in the cross section cut along the thickness direction of the substrate, the outer peripheral seal portion covers and seals the end surface in the length direction of the transparent conductive film from the outside. A dye-sensitized solar cell, wherein the second backsheet portion has a backsheet cover portion that covers the covering portion of the outer peripheral seal portion from the outside.

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